She was converted to Christianity by Saint Birinus, along with King Cynegils of Wessex, in 635. Her legend in the York Breviary states that she was of the Wessexnobility. She fled from home to become a nun, and was joined by Saints Bega and Wuldreda. Saint Wilfrid of York made them all nuns at a place called the Bishop's Dwelling, later known as Everildisham. This place has been identified with present-day Everingham. She gathered a large community of some eighty women.
^"Everilda" in Frances Egerton Arnold-Forster, Studies in church dedications: or, England's patron saints, 1899:403f, based on Acta Sanctorum, "setting forth three lessons on the saint". Also Everildis.
^David Hugh Farmer, ed. The Oxford Dictionary Of Saints, s.v. "Everild (Everildis, Averil)".